Conventional methods are known that detect a character string written on a name board, a sign, a menu of a restaurant, and others from an image acquired by imaging the character string with a built-in camera in a smartphone, a tablet, and the like.
The conventional techniques, however, have difficulties in accurately detecting a character string with a simple operation input. For example, even if all detection fields indicating character strings can be detected from an image, if the image includes a plurality of character strings, the user needs an operation input to accurately designate his/her target character string from the detection fields. For example, refer to Japanese Patent Application Laid-open No. 2016-004553, Japanese Patent Application Laid-open No. 2016-045877, and Tonouchi Y., Suzuki K., Osada K., A Hybrid Approach to Detect Texts in Natural Scenes by Integration of a Connected-Component Method and a Sliding-Window Method, IWRR 2014 (Singapore).